Guys with thick wallets often get a complete big brake kit from one of the reputable manufacturers, and while this is a sensible route to take, it’s not the only one. Not to disparage the benefits big brake kits offer, but they’re generally quite pricey, and the ambitious amateur who wants a little more in the braking department doesn’t necessarily need to spend an arm and a leg. Now, braking performance can be broken down into several categories. It’s not just braking power that defines a good set of stoppers, but their ability to be modulated, and their resistance to fading are equally important. For braking performance, it’s always worthwhile considering the mass of the vehicle, since something that’s light doesn’t need as much friction to slow it down. For that reason, putting a car on a diet is always a good idea. Let’s face it: cars with plush interiors, large bodies and massive motors generally mean lots of heft, and if a car is going to stop like a Lotus Elise, it needs to get a little closer in the chub department. Fiberglass hoods and trunks, lighter sport seats, and lightweight wheels all contribute towards shorter braking distances, and incidentally, make the car a quicker accelerator, too.
It’s the last of those suggestions which offers more than just a reduction in braking distances. Lighter wheels mean a reduction in unsprung mass, which has the benefit of providing better braking over bumpy surfaces. Lightweight wheels have less inertia when moving up and down as the shock absorber compresses and extends over bumps, and therefore minimize the range of motion, assuming the spring rates are correct. This means that as a wheel moves over a series of bumps or undulation in the road, it will skip less and maintain a more consistent contact patch on the surface of the road. When it comes to consistency in braking power and durability of the brakes, having a good set of brake lines goes a long way. As the braking fluid is heated during hard stops, the factory lines, which are usually made of a very malleable material, expand and pressure in the lines is reduced, hence the brake pedal going soft and eventually going all the way to the floor if there’s too much heat in the braking system. Upgrading to steel-braided lines, which retain their shape better even when the fluid is scorching hot, will give the driver the ability to brake harder for a greater number of times before diminished braking power is noticeable.
One need not stop at the lines if they’re looking to minimize brake fade. High-performance brake fluid, which is harder to compress, is available from most speed shops. This not only gives the brakes better stamina, if you like, but it ensures a detailed feel on the pedal. Generally speaking, this will offer a shorter pedal travel that requires a little more effort, but twice the detail coming through. What this translates to is a better feel on the limit of adhesion, and an improved ability to modulate brake lock-up. Dissipating heat from the brakes is another way to keep them fresh over the course of a hard run. What some serious builders and any competitive road racer will do is add a set of brake ducts to feed the rotors with a constant supply of fresh air. This means cooler brakes, less brake dust, and more consistent braking performance over a series of hard stops.
However, lowering the temperature of the brakes too far can be a problem, depending on the pads used. People serious about braking performance will opt for a set of performance pads, which are very reasonably priced and provide huge gains in the braking department. However, high-performance or racing pads are usually designed to work in a narrow temperature range, and while they provide greater resistance to fading, usually need to be warmed up more than typical street pads, which offer good initial bite but low fade resistance, before they offer much bite. For this reason, brake ducts can keep the extreme track-oriented pads from getting up to their operating range, though that’s unlikely to be an issue for anyone other than serious road racers.
The brake pad’s performance is dictated somewhat by the surface area it’s in contact with. Moving to bigger rotors will improve braking power, since it generates more friction, and it further reduces brake fade, though the rotors need the proper cooling channels for the gasses to escape through. Big brakes with slotted rotors give the heat and gasses avenues to leave the rotor, which allows for better contact between the pad and the rotor, since said gasses and particles can form a layer between the two agents and keep them from contacting correctly. We’ll avoid delving into tires and suspension, but a stickier tire will generate more grip on the road, and a good suspension setup will keep the tire in contact with the road more of the time, as well as improve the tire’s contact patch. All of these ingredients play an important role in the overall performance of the brakes, and most of them are intertwined.
It should be said that improperly modifying the brakes can be dangerous. For instance, with greater braking force comes more heat, and so the modifications need to be made to accommodate all the demands of the brake package. Not every brake pads interacts well with any tire or any brake fluid, and so if someone decides to build a brake system themselves, they need to acquaint themselves with the specifics. For those who don’t, the complete kits might provide a simple and effective way to feel more comfortable with their muscle car and chip away at lap times. However, sometimes they’re not as effective as one might think. Ultimately, it’s the combination of a good set of pads, good cooling, a performance-oriented brake fluid, and a good suspension setup that will give one the confidence they need to push their car to the limit.
Hard braking in turn 6.